Method of making reenforced blocks



Nov. 6, 1928.

L. w. CAFFERATA 1690474 METHOD OF MAKING REENFORCED BLOCKS Filed June 15, 1925 Invnvl lauw Wmzm Patented Nov. 6, 1928.

UNITED STATES LoUIs WILLIAM CAFFERATA, or NEWnnK-oN-TRENT, ENGLAND.

METHQD 0F MAKING REENFORCED BLOCKS.

Appuemon med June 15, 1925. serial No. 37,177."

The general subject matter ofk my present invention is the production of a new type of plaster block or building block especially such as having plaster or lime or a combinationof each as its principal cementing medum. l,Vith such I combine as a novel reenforeement, a fibrous medium of nonsrigid form, in such a way as greatly to increase the strength of the block while preserving and even increasing certain other characteristics.

rlhe several elements of novelty, in my invention, appear in the product, in certain desirable characteristics of product incident to its use and generally in a system of' reenforcement with the resilient, fibrous material introduced into the plastic composition of the block and fabricated therein during the process of pouring and molding ot the block or slab. 4

The so-called gypsum block or plaster block or tile has been familiarly known and increasingly .used in the building material and construction trades in recent years. From a small beginning the growth in the use of this product has been rapid, until at the present time many million square feet of these block or tile are being used each year in the United States, for construction work as partition tile and general insulating purposes.

These gypsum blocks or tiles are manu` factured from commercial plaster of Paris by mixing approximately equal proportions of the plaster of Paris and water and pouring the mixed magma into molds, having removable rods or mandrels which serve the purpose of making the core holes in the block. Practically all of the plasterblocks manufactured in the UnitedV States, above the twoinch thickness, are made in hollow form or having core holes or hollows. ,The purpose of the hollows is yto make a lighter block and at the same time to use a lesser amount ot plaster of Paris per given unit of block. Also. a hollow block dries or cures more quickly than the `solid block. The breakage, however, in removing these hollow blocks from their molds and in further handling them during process oit transportation to the job, is very considerable.`

My invention `contemplates the elimination of or reduction in breakagev and at thehsame time greatly increasing the compressive strength and toughness of plaster blocks, the reeni'orcing of the block throughout its 55 length and breadth by embedding in the plaster mixture,during process ofk pouring, a fibrous, non-rigid substance such as; rus reeds, or rattan fibre. or similar materials of cellulose composit-ion. y g

To such a fibrous material the plaster composition bonds tenaciously, even `during the preliminary casting and hardening of the plaster composition used in the blocks, to such an extent that within fifteen to twenty minutes afterpouring the plaster magma in molds or on continuous belts, and thereby forming a reenforced plasterA block or slab, said slab may be sawed (1r/otherwise cut into standard lengths without breaking the bond between the fibre` reenter-cement and the plaster mixture. i

Another advantage of this fibre reenforcement is due to its resiliency which permits the plaster block or slab thus reenforce'd to show a certain deflection or 'bending movement without breaking away from the plaster bond. n

Fibrous materialsuch as the rush reed, or rattan fibre strands are porous in texture and when embedded within a plaster mixture, suitable forblocks, permit an immediate inteihgrowthof the plaster crystal among the interstices of the fibre reenforcementand to this fact, as well as to the rough texture of 8f these reeds or rattan strands, great binding strength is derived. i

. Another featureof my fibrereenforced blocks is in their lightness as compared to a solid nonreenforced block or slab, as the fibre strands distributed y throughout the width of the block or slab` replace just so much .ofthe heavier plaster mixture, lighten the block and to all intents'and purposes serve theisame as the core holes in the hollow block but give more thandouble the strength of the hollow block. y

` I find again that for,y certain types 1 of plaster, such as the pla-ster recovered from byproduct or precipitated gypsum, which when converted into, plaster of Paris, is inclined to bevery iinely divided and makes a more porous and less dense plaster slab. Said slab made from such plaster is apt to be weak and the only possible way of manufacturing a plaster block which will pass standard specifications for strength, from such plaster, is by myibrey reenforcement. Furthermore, such ree'nforcemen't is practically self-adjusting for position in the block so as to require very little manipulation and in. spite of. `its strength is severable without dlliiculty andv without disturbance' off its. relationr in the block. I

To make mv invention clear' in itsgeneral yapplicabilityfI will show and kdiscuss the plaster block instancey above referred to, as that) is not only indicative" of general use, but vinv itself is a highly'successful specific case. Throughout the specification and'drawings like reference characters'are employed to indicate corresponding parts, and in the drawings:

Fig.y 1 is a sectional view of a block in accordance with my invention.

a diagrammatic view showing the characteristic formation of a block slab,y and 'F1g. 3 a similar view showing the cutting of the same.

`For a block or unit illustrative'of'my invention I have showna block of general type, rectangular in cross section and of greater length than height or breadth. I show such av'form as itis characteristic. Vithin this Il' block 1 I have indicated at 2 my reenforceyment which issho'wn as extending generally longitudinally ofthe block and in general parallelism, although I have shown this as beng'somewhat irregular as there is an advantage in having the individual reenforcing units disposed in somewhat 'of a crossed relation so as to secure a greater bonding and a greater resistance to strains whichare 'apt' to be symmetrical to they faces of the block. Y

VThis reenforcement 2 is introduced during themolding as indicated in'Fig. 2` ofthe drawings. In these drawings I'have shown a belt type of mold consisting of lateral mold pieces M and a bottom Ml into which the miXed plaster of Paris orlike material is discharged in Huid state from a container C.

lThe discharge is so timed andvregulated as toy fillk the'belt mold yas it moves along the Acourse of its travel, which 'is of suilicient length to give the plastertime to set before 'it is vcut up.

This brings us to the point of the type of yreenforcement contemplated by my invention. For that purpose, I utilize sections of plant growthA in thek form of stalks or sheets. There are a great variety of such growths pmore .or less available and of more or less desirability as regards several factors that are controlling.l It isimpossible for me to f catalog here all of suchy growths, but I will first' describe the' desired7 characteristic and then give instances of some of those that sec-m most satisfactory.

In the first place, such growth is preferably light and of considerable buoyancy and either by its nature free from bark or husk or readily stripped thereof. It is preferably of' strong longitudinal fibre and while absolute straightness is not necessary, a general straightness isdesirable and convenient. For the best results the surface should be easily wetted. andpreferablv permeable by water so as to increase the elhciency of the bonding ofA the reenforcement in the wet plaster as are not'usable and have heretofore been `regardedin large part as waste.

Considering now such a material, it will be seen that it can be laidin` themolds as they are filled with the fluid plaster, extending longitudinallyand largely in a natural arrangement by theirindividual powerof flotation. I have indicated at P any means of submerging this reenforcement andfthis subi merging action usually should 'continue until the plaster begins to s et slightly so as to secure a `distribution of thereenforcement I through the block inthe direction of itsk depth; The reenforcement should be laid in preferably with a slight overlapping or splicing effect so that the reenforcement longitudinally of the slab for any given length will be practically continuous in.. its overlapped, as wellV as its interlaced condition." This produces in the slab a reenforcement of great lcontinuity and strength.V

The cutting of. such a slabso` reenforced may be accomplished without theslightest diiliculty or the slightest disturbance to the bondingof the reenforcement.k Ihave indicated at4 S a saw which is moved intermittently to cut the slab into sections of the desiredl length. These may theny be loaded on trucks and run through driers where the final setting is completed Such blocks are of great strengthA andlightness'and are produceable at low cost. "f j y Various modifications may obviously be made inthe form ofthe block and' in the manner of its formation, as well as in the selection of the material to be used as reenforcement, all without departing from the spirit` of my invention if within the limits of the appended claims.

kWhat I therefore claim and ydesire to secure by Letters Patent is: l, The method of making plasterof Paris blocks, consisting in placing in a mold a buoyant reenforeement and in filling the mold with Huid plaster and keeping the reenforcement submerged until held by the set of the plaster.

2. The method of making plaster of Paris bloc-ks consisting in feeding to a moving mold a reenforcement of plant stalks disposed longitudinally thereof, in illing the mold With fluid plaster as it moves to form a slab With 10 the reenforcement embedded therein, and in transversely cutting the slab into blocks of the required length.

In testimony whereof I allix my signature.

LOUIS WILLIAM CAFFERATA. 

